Creosote is a category of carbonaceous chemicals formed by the distillation of various tars and pyrolysis of plant-derived material, such as wood, or fossil fuel. They are typically used as preservatives or antiseptics.
Wood railroad ties before (right) and after (left) infusion with creosote, being transported by railcar at a facility of the Santa Fe Railroad, in Albuquerque, New Mexico, in March 1943. This U.S. wartime governmental photo reports that "The steaming black ties in the [left of photo]... have just come from the retort where they have been infused with creosote for eight hours." Ties are "made of pine and fir... seasoned for eight months" [as seen in the untreated railcar load at right].
Portrait of Bishop Berkeley by John Smybert, 1727
Wooden street pavers in Chicago
Broken creosote piling exposed by weathering
Tar is a dark brown or black viscous liquid of hydrocarbons and free carbon, obtained from a wide variety of organic materials through destructive distillation. Tar can be produced from coal, wood, petroleum, or peat.
One can produce a tar-like substance from corn stalks by heating them in a microwave oven. This process is known as pyrolysis.
Tar kiln at Trollskogen in Öland, Sweden
Birch tar
A boat transporting pine tar barrels on Oulu River in 1910
